I run a gaming channel, part of it is about teaching how to play parts of the game and part of it is about entertainment. My own children watch gaming videos on YouTube regularly, but very rarely watch any television channels. When I say rarely, I mean at most, once in 3 months. It's an alternative to older forms of entertainment. Personally I don't like watching channels like PewDiePie because of the over excited bad language that's poured out in a constant barrage. But just keep in mind that there are a lot of gaming channels that don't use that approach! I have quite a lot of viewers that watch my daily videos as an alternative to TV. That's people of all ages, different backgrounds, country or origin etc that will watch me instead of TV, because there is now that choice available. I remember growing up sitting and watching a program in the evening that I wasn't particularly interested in because there wasn't anything else on and I didn't have the energy to go and do something else. We don't have that now, people can pick entertainment from all types.
As for which channel I hate, mainly it's the troll channels where late teen and early 20's gamers target young gamers in online games that allow mic communication between players and then bully them until they cry. I despise those channels and gamers and really think YouTube should do more to stamp them out.